Mission-critical communication with LTE450 in energy areas in the North Sea.

There is an increasing amount of economic activity at sea. Besides transport ships, the North Sea is also seeing a rise in wind farms, energy hubs, and - in the future - food production facilities. This development is leading to a growing demand for communication and digital connectivity, which in some cases can be critical for businesses. At sea, the availability of communication networks is more limited compared to land. This study aims to answer the main research question: **What are the opportunities and barriers for developing a mission-critical voice service based on LTE450 in the Dutch part of the North Sea?** The answer to this question is structured around a SWOT analysis for a hypothetical future LTE450-based mission-critical service, as well as four specific questions described below. ### Strengths and Weaknesses, Opportunities, and Threats The key strengths, weaknesses, opportunities, and threats for a mission-critical LTE450-based voice service at sea are as follows: - **Strengths**: The 450 MHz band can enable mission-critical communication at sea. There is a global momentum for using LTE/5G in the 450 MHz band for both data and voice communication, primarily driven by the utility sector. Coverage at sea can be achieved relatively quickly using spectrum in the 450 MHz band. Spectrum availability is secured until at least 2050 due to the current allocation to Utility Connect. The impact of interference seems limited and manageable. - **Weaknesses**: The 450 MHz band is not standard in regular LTE/5G devices. The ecosystem for handsets supporting LTE450 is much smaller compared to regular LTE and 5G bands. Utility Connect will be able to deploy only one carrier based on LTE-M until July 2035 (on land). However, 3GPP standardized mission-critical voice (MCX) is unlikely to be supported in combination with LTE-M. - **Opportunities**: There is limited digital connectivity available at sea, making LTE450 a good "ultimate fallback option" for critical voice and IoT communication with low data volume. The LTE450 network could be fully independent of other public mobile networks, offering advantages in terms of control, security, and lifecycle management. Deployment of 3GPP MCX can also provide valuable insights for VMX, the successor to C2000 (the current Dutch PPDR mobile communication system based on TETRA). - **Threats**: Alternatives at the North Sea are becoming more available, but most cannot (yet) meet mission-critical requirements. These include public mobile networks in "regular" LTE/5G bands and direct-to-device satellite communication. Their availability is good news for users needing digital connectivity at sea, but it means that the LTE450 network could eventually be overshadowed. On one hand, relatively affordable broadband connectivity is becoming available for non-critical applications, acting as a fallback or standard option for critical applications. Satellite communication can provide the ultimate fallback option for critical voice communication. On the other hand, (local) narrowband networks may be easier to implement or adapt to specific situations, depending on the scenario. Access to public mobile networks at sea would provide access to a much larger ecosystem, more choice, and connectivity with VMX. The key point for the future viability of LTE450 at sea is its positioning and added value compared to available alternatives. Globally, there is a trend towards using a mix of both public infrastructure (mobile networks) and specific spectrum and infrastructure for PPDR networks. LTE450 could serve as an "ultimate fallback option" by providing limited capacity but high reliability (especially in emergencies). However, this can also be achieved through satellite connectivity (direct-to-device). Another disadvantage of LTE450 is the limited handset ecosystem and the need to establish and maintain a radio network at sea. With all other options, standard handsets can be used, and the existing network infrastructure can be leveraged. ### How feasible is it to ad-hoc pair TETRA-based handsets with LTE450 handsets in mission-critical first responder/PPDR applications? TETRA networks can be paired with 3GPP MCX-based systems, enabling users on both platforms to communicate with each other. However, there are no handsets available that support both TETRA and LTE450, so responders cannot use a single device to connect to C2000 on land (using TETRA) and via the LTE450 network at sea (unless ad-hoc C2000 TETRA base stations are set up at sea, with LTE450 or the aforementioned alternatives for backhaul connectivity). ### How sustainable is the 2x3 MHz spectrum allocated to Utility Connect until 2050 concerning the usability of 3GPP technologies (LTE450 and successors)? Utility Connect has secured availability of the 2x3 MHz spectrum until 2050. However, limited use can be made of it on land until 2035 due to the need to maintain a CDMA450 carrier. Based on the available 1.5 MHz spectrum at that time, there are limited opportunities to realize a mission-critical voice service (in terms of capacity and support for LTE-M voice equipment). ### How does a mission-critical mobile network for PPDR based on LTE450 fit into European harmonization and interoperability developments like BroadEU.net and the EU Spicenet reference architecture? The reference architectures developed at the European level provide a framework to interconnect different types of PPDR networks, including TETRA and 3GPP MCX, at a higher level. Based on these developments, we see no limitations regarding the achievable LTE450 network. In practice, the implementation of the mentioned reference architectures seems to be barely underway. ### What limitations can be expected regarding the use of LTE450 in the North Sea, concerning interference from and to foreign usage in and around the 450 MHz band? First and foremost, consideration should be given to the UK's usage, which is usually narrowband in nature. Particularly, the 450 band in the UK is configured in a way that uplink and downlink are precisely opposite to those in the Netherlands. The impact on the network from the UK (and even Belgium, where the entire 450-470 MHz band is used for PMR) is expected to be limited or easily mitigated. Broadband LTE and 5G technology are relatively robust to narrowband interference. An LTE450 network at sea could also be designed so that base stations (targeting the Dutch mainland) emit the least signals towards the UK and receive as few as possible. Conversely, the network may hinder narrowband users across the border, serving as a limiting factor.